1. Field
The following description relates to a rechargeable lithium battery having a controlled particle size ratio of activated carbon to a positive active material.
2. Description of the Related Art
Recently, due to reduction in size and weight of a portable electronic equipment, and popularization of portable electronic devices, researches on rechargeable lithium batteries having high energy density for power source of portable electronic devices have been actively made.
Rechargeable lithium batteries include a negative electrode, a positive electrode, and an electrolyte, and generate electrical energy by oxidation and reduction reactions when lithium ions are intercalated/deintercalated in the positive electrode and negative electrode.
Such rechargeable lithium batteries use a lithium metal, a carbon-based material, Si, or the like for a negative active material.
For a positive active material of rechargeable lithium batteries, metal chalcogenide compounds capable of intercalating and deintercalating lithium ions, for example, composite metal oxides such as LiCoO2, LiMn2O4, LiNi1−xCoxO2 (0<X<1), LiMnO2, or the like have been used.
Recently, an attempt has been made to obtain low electrical resistance by making an electrode into a thin film and thus, to accomplish high power characteristics for a rechargeable lithium battery may be realized. However, this approach is not satisfactory yet due to characteristics of the active material itself. Accordingly, a technology of adding activated carbon as a capacitor material to an active material has been developed.